Hi Natalie, my wife has Chiari and the surgeon that operated on her 2 weeks ago said that it was the worst he had ever seen. But to answer your question ACM0 and ACM1 do not have seizure activity. ACM 2 and ACM 3 do my wife had ACM2 borderline 3 according to the surgeon.
She had many issues with this she was diagnosed with ACM1 4 years ago so my advise is to see a neurosurgeon as soon as you can.
I only know this from experience as my wife is now fighting for her life in the Hospital so please get taken care of soon but checked out soon.
My prayers are with you God Bless
Arnold chiari I malformation is a condition where the hind brain enters the upper part of the spinal canal resulting in cerebellar symptoms (gait abnormalities, coordination problems, balance problems, vertigo). Obstruction of the CSF can result in headaches, decreasing sensorium and a serious complication of this is herniation. Seizures can also occur. The diagnosis usually relies on signs and symptoms and imaging studies especially MRI.